The present invention relates generally to knockout window structures for electrical assembly boxes and more particularly to integrally molded knockout window structures for electrical assembly boxes made from a moldable plastic material.
Electrical assembly boxes, such as electrical outlet boxes, electrical junction boxes, fuse boxes and other electrical appliance enclosures are usually mounted in walls or ceilings with their front face generally flush with the wall or ceiling for supporting an electrical receptacle, switch or other device which is to be electrically coupled to the circuitry of the room. Electrical conductors are therefore run into the box through apertures formed therein, for coupling the device to such circuitry. However, in order to prevent construction related debris from inadvertently falling into the box before insertion of the electrical cable, and to protect the apparatus mounted therein from the introduction of debris through apertures which are not utilized, even after installation, knockout window structures have been provided in the walls of the structure to cover or close such apertures until the conductors are to be installed.
Some typical electrical assembly boxes consist of die cast metallic housings or molded plastic housings provided with knockout panels which must be removed through the application of a substantial impact or force from the outside. Other structures include knockout window means which are usually accessible from either only the inside or only the outside, and/or which include just one structural member accommodating insertion of a panel removal tool. Thus, once a portion of the panel is broken away from such box structure, the panel usually remains hinged thereto so that complete removal of the panel may be achieved only after additional awkward manipulations, either with tools or by hand. No known knockout window structure has been disclosed which includes removal means for effecting complete removal of the panel in a simple and convenient operation, and for enabling complete removal of the panel from both the inside and the outside of the electrical assembly box.
It is therefore an object of the present invention to provide a new and improved knockout window structure.
Another object of the present invention is to provide a new and improved knockout window structure integrally molded in a unitary electrical assembly box made of moldable plastic material.
It is also an object of the present invention to provide a new and improved knockout window structure in which the knockout panel may be completely removed by convenient means.
It is a further an object of the present invention to provide a new and improved knockout window structure in which the knockout panel may be removed from both the inside and the outside of the assembly structure.
It is still another object of the present invention to provide a new and improved knockout window structure in which the knockout panel may be completely and easily removed yet is connected to the electrical assembly box with sufficient structural integrity to withstand falling debris and other impact during installation of the box.
Objects and advantages of the invention are set forth in part herein and in part will be appreciated herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.
The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.